Hawthorn
Botanical Name
Crataegus monogyna
Family
Rosaceae (rose)
Also known as
Whitethorn, white hawthorn
Where is it originally from?
Europe
What does it look like?
Deciduous shrub or small tree (<10 m tall) with much-branched stems that are hairless, reddish-brown when young, but become grey when mature and have stiff spines to 12 mm long. Hairless triangular leaves (35-50 x 35-45 mm) with 3-7 deep lobes are solitary on long shoots, clustered on short shoots, and are often chewed by slugs. Dense flat clusters of 6-15 sweet-scented, white (rarely reddish-pink) 5-petalled flowers (10-15 mm diameter, Oct-Nov) are followed by round, shiny, crimson berries (7-11 mm diameter, Dec-Apr) with little flesh around a single stone.
Are there any similar species?
Other cultivars, especially Crataegus laevigata (usually grown as pink, double flowered cultivars), barberry and boxthorn are similar.
Why is it weedy?
Produces many long-lived, well dispersed seeds, is extremely tough and versatile, long-lived, tolerates hot to cold temperatures, damp to dry conditions, salt, wind, heavy damage, most soils, and semi-shade.
How does it spread?
Birds, and occasionally soil and water movement. Hedges, poor pastures, roadsides, and waste places are all seed sources.
What damage does it do?
Crowds out most other species, forms dense (occasionally pure) thickets, preventing the establishment of native plant seedlings.
Which habitats is it likely to invade?
Disturbed forest, shrubland and margins, fernland, wetland margins, short tussockland, other low-growing habitats, and cliffs.
What can I do to get rid of it?
1. Physical removal - Hand pull small plants, or dig out entire plant including roots (all year round): Burn, dispose of to refuse or leave on site to rot down
2. Cut and paste (all year round) - Cut the stem/trunk as close to the ground as possible and cover the entire stump with herbicide as soon as possible after cutting. Apply either glyphosate gel (120g/L strength) or metsulfuron gel (10g/l strength) or picloram gel (43g/l strength) to the entire cut stem.
3. Basal spray - Basal spray stems up to 20cm diametre with X-Tree Basal. Apply from the ground to a height of 6 times the diameter of the plant, ensure the base is thoroughly covered at ground level.
4. Drill or frill - Drill downward sloping holes around the circumference of the trunk about 8-10 cm apart, or Frill (make deep cuts into the sapwood at regular intervals around the base of the tree, taking care not to ring-bark the plant). Fill the holes or saturate the cuts with a product containing 100g picloram+300g triclopyr/L (undiluted).
5. Foliar spray - Apply herbicide using a handheld sprayer/knapsack to plants <1m tall or gun and hose for larger infestations. Use the label recommended adjuvant.
Apply metsulfuron herbicide (600g/kg active ingredient at 0.5g/L knapsack or 20g/100L gun and hose) plus organosilicone penetrant (3ml/L) Note: Metsulfuron overspray will kill other (desirable) broadleaf plants and has residual activity in the soil which aids in killing below ground parts.
CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and directions for the purchase, use and storage of the product, are followed and adhered to.
What can I do to stop it coming back?
Cut stumps and severed roots resprout. Plants prefer disturbed soils, are slow to die and decompose. Avoid temptation to clear, burn or otherwise disturb soil. Maintain humus and groundcover. Plant dense species where possible to minimise seeding.
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